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Biomedical subjects

K M Rao

Publications and source records attributed to K M Rao.

At least 19 recordsLinked to original sources
PubMed2003

The in vitro and in vivo development of goat embryos produced by intracytoplasmic sperm injection using tail-cut spermatozoa.

The objective of this study was to assess the efficacy of a novel intracytoplasmic sperm injection (ICSI) procedure, as well as the in vitro and in vivo developmental competence of goat embryos produced by ICSI. Oocyte-cumulus complexes recovered by LOPU from donors stimulated with gonadotrophins were matured in vitro. Fresh goat semen was used for ICSI following Percoll gradient washing. Tail-cut spermatozoa were microinjected into the ooplasm of goat oocytes using a piezo micropipette-driving system (PiezoDrill). In order to assess developmental competence, the ICSI-derived zygotes were cultured in one of two media systems (mTALP-mKSOM vs G1.3-G2.3) for in vitro development or were transferred into recipients for full-term development. The results suggest that cutting sperm tails using the oocyte-holding pipette coupled with the PiezoDrill is an efficient approach for goat ICSI in terms of oocyte survival, pronuclear development and initial cleavage. The mTALP-mKSOM culture system was more suitable for in vitro development of ICSI-derived goat embryos than G1.3-G2.3. This first report of full-term development of an ICSI-derived goat embryo suggests that ICSI can be applied to assisted reproduction in goats.

Animals↗
PubMed2001

Intraspinal neurenteric cysts--report of three paediatric cases.

BACKGROUND: Neurenteric cysts are rare congenital lesions of the spine and are lined with entodermal epithelium. They result from anomalous endodermal-neuroectodermal adhesion in the 3rd week of embryonic life with persistence of canal of Kovalevsky. The nature of the eventual abnormality depends on the extent to which this adhesion subsequently disappears. Persistence of the entire tract results in the extreme form of combined anterior and posterior spina bifida with dorsal enteric fistula and persistence of only a part of the tract producing the isolated intraspinal cyst. The most common location is the cervico-dorsal region, and usually it lies ventral to the spinal cord. The lumbosacral location is uncommon. Associated vertebral anomalies, gut cysts, bowel duplication, the presence of keratin markers and mucin-secreting cuboidal or columnar intestinal epithelium in their walls confirm their entodermal origin. PATIENTS: We describe here three unusual cases of neurenteric cysts in patients aged 5-18 years who had already had symptoms for some time. One of these had a cyst sited predominantly in the sacral canal, another presented with a lumbar neurenteric cyst, and the third patient had an intradural extramedullary thoracic lesion. Two of these children had associated anomalies, the one with lumbar cyst also having a lipomeningomyelocele and spina bifida while the other also had deformed vertebrae. All three patients underwent laminectomy and gross excision of the cysts through a posterior approach. RESULTS AND CONCLUSION: The diagnosis of neurenteric cysts was confirmed by demonstrating mucin-producing cuboidal or columnar epithelium lining the cystic cavity.

Adolescent↗
PubMed2001

Control of the buffalo fly Haematobia irritans exigua in India, using the pyrethroids deltamethrin and fenvalerate.

The effectiveness of two pyrethroids, fenvalerate and deltamethrin, against the fly Haematobia irritans exigua de Meijere (Diptera: Muscidae) on buffalo was considered in a field trial. Fenvalerate provided 100% control for 1, 2 and 4 weeks at concentrations of 0.03, 0.04 and 0.05%, respectively. Concentrations of 0.01 and 0.02% were less effective. One hundred percent control of this fly was obtained with deltamethrin for 2, 3 and 6 weeks at concentrations of 0.003, 0.004 and 0.005%, respectively. Deltamethrin concentrations of 0.001% and 0.002% achieved fly control for only 1-2 weeks, respectively.

Administration, Topical↗
PubMed2001

MAP kinase activation in macrophages.

Stimulation of macrophages by a variety of agents causes activation of mitogen-activated protein kinases (MAPKs). Activation of MAPKs by lipopolysaccharide involves CD14 and Toll receptors. Subsequent steps still remain to be explored. Tumor necrosis factor-alpha (TNF-alpha)-induced activation of MAPKs has been shown to involve the death domain proteins (TRADD, FADD, MADD) and TRAFs. Other molecules involved in this pathway include the protein kinases, ASK1, germinal center kinase (GCK), hematopoietic progenitor kinase 1 (HPK1), and GCK-related kinase (GCKR). Although, these pathways have been described in various cell types, their role in macrophages remains to be established. The availability of knockout mice and constitutively active and dominant-negative mutants of MAPKs should greatly enhance our understanding of this field. The activation of MAPKs seems to be different in cell lines compared with primary cells. Among the macrophages, cells from different compartments show different expression of receptors and signal transduction molecules. These differences may account for differences in MAPK activation and other phenotypic differences in macrophages from different compartments. Therefore, it is important to use primary cells for studying MAPK signal-transduction pathways, and the data from cell lines should not be extrapolated to primary cells.

Animals↗
PubMed2000

Lung responses to hypothyroidism, hyperthyroidism, and lipopolysaccharide challenge in rats.

The objectives of this investigation were to study the effects of hypo- and hyperthyroidism on some factors involved in lung injury under basal conditions (air exposure) and during an inflammatory response induced by inhalation exposure to lipopolysaccharide (LPS; 100 microg/ml; 3 h) in adult rats. Thyroid status was altered by thyroidectomy or thyroxine injections for 15 d. Hyperthyroidism alone caused a greater degree of lung cell damage, an increase in the permeability of the alveolar-capillary barrier, a rise in the total number of phagocytic cells obtained by bronchoalveolar lavage (BAL), and enhanced nitric oxide (NO) release by phagocytic cells relative to that in euthyroid control animals. Hypothyroidism alone was associated with opposite effects. Exposure of animals to LPS produced inflammatory responses, which included significant increases in lung cell damage, permeability of the alveolar-capillary barrier, number of phagocytic cells obtained by BAL, and NO production by the phagocytic cells. In general, hyperthyroidism enhanced the effects of LPS, while hypothyroidism reduced LPS-induced responses. These results suggest that thyroid status alone can affect some of the factors involved in lung injury and also modulate some of the inflammatory effects of LPS. Hyperthyroidism tends to enhance lung injury, while hypothyroidism seems to reduce lung injury.

Albumins↗
PubMed2000

Age, functional status, and racial differences in plasma D-dimer levels in community-dwelling elderly persons.

BACKGROUND: Dysregulation of immunologic and coagulation systems is common in elderly persons and is associated with many diseases of aging. Thrombotic events are a major cause of morbidity and mortality in the elderly population. This study assesses whether D-dimer, a marker of fibrinolytic activity, varies systematically by demographic, health, and functional measures, and derives a prediction model for factors related to D-dimer in a sample of community-dwelling elderly persons. METHODS: D-dimer levels were assessed in a random sample of 1,727 community-dwelling elderly persons from five rural and urban counties in North Carolina in 1992, as part of the Established Populations for the Epidemiologic Studies of the Elderly (Duke University). All subjects were 72 years or older at the time of the blood draw. In addition, all subjects were surveyed yearly by telephone or in person each year from 1986 to 1992 for a variety of health, functional, and social factors. Levels of D-dimer in 1992 were related cross-sectionally to demographics (age, race, education, income, gender, smoking), function (Nagi, Rosow-Breslau, Katz, Older Americans Resources and Services procedures instrumental activities of daily living), life satisfaction and self-rated health, self-reported diseases (heart attack, cancer, stroke, diabetes, and hypertension), and weight change from 1986 to 1992. RESULTS: D-dimer levels increased with increasing age and functional disability. Among the health variables, only high blood pressure was predictive of D-dimer level. D-dimer levels were dramatically higher in blacks. Blacks were nearly four times more likely to have an extreme value of D-dimer (>600 microg/l) than whites when high D-dimer (yes/no) was analyzed, and blacks had an average level that was nearly 40% higher than whites in analyses of the continuous version of the outcome. This racial effect was not substantively affected in multivariable analyses with demographic and socioeconomic variables controlled. Race, age, functional status, current smoking, high blood pressure, and weight loss were related to level of D-dimer, and race, age, and functional status were related to the presence of a high D-dimer level (in the top 10% of the sample). CONCLUSIONS: Black, older, and functionally impaired persons had significantly higher levels of D-dimer in this sample of community-dwelling elderly persons. The findings for race were particularly striking and persisted even after controlling for smoking and other factors known to be related to thrombosis and were not mediated by social factors. This result may contribute to our understanding of the increased levels of thrombotic events found in these groups.

Aged↗
PubMed2000

Changes in F-actin organization induced by hard metal particle exposure in rat pulmonary epithelial cells using laser scanning confocal microscopy.

Chronic inhalation of hard metal (WC-Co) particles causes alveolitis and the eventual development of pulmonary fibrosis. The initial inflammatory response includes a change in the alveolar epithelial cell-capillary barrier, which has been shown to be regulated by the state of assembly and organization of the actin cytoskeletal network. The objective of this study was to evaluate the effect WC-Co particles have on F-actin organization of lung epithelial cells in an in vitro culture system. Rat lung epithelial (L2) cells were exposed to 5, 25, and 100 microg/mL of WC-Co particles, as well as the individual components (Co and WC) of the hard metal mixture particles for 24 h. The effect on F-actin organization was visualized by laser scanning confocal microscopy (LSCM) following Bodipy-Phallacidin staining. Minimal changes in the F-actin microfilaments of L2 cells were observed by LSCM after exposure to WC and WC-Co at 5 and 25 microg/mL, while at 100 microg/mL, there was a noticeable disruption in the uniform distribution of L2 cell F-actin microfilaments. After exposure to Co, a dose-dependent change in the F-actin organization of the L2 cells was observed. Little change in F-actin assembly was observed after treatment with 5 microg/mL of Co (the concentration equivalent to the 5% amount of Co commonly present in 100 microg/mL of the WC-Co sample mixture). However, at 100 microg/mL of Co, the microfilaments aggregated into homogeneous masses within the cells, and a significant loss in the organization of L2 F-actin was observed. These dramatic alterations in F-actin organization seen after exposure to the higher doses of Co were attributed to an increase in L2 cell injury as measured by lactate dehydrogenase and trypan blue exclusion. We conclude the pulmonary response evoked in the lung by inhalation of high levels of WC-Co particles is unlikely due to alterations in the F-actin microfilaments of lung-epithelial cells.

Actin Cytoskeleton↗
PubMed1999

Pulmonary surfactant inhibits LPS-induced nitric oxide production by alveolar macrophages.

The objectives of this investigation were 1) to report that pulmonary surfactant inhibits lipopolysaccharide (LPS)-induced nitric oxide (. NO) production by rat alveolar macrophages, 2) to study possible mechanisms for this effect, and 3) to determine which surfactant component(s) is responsible. NO produced by the cells in response to LPS is due to an inducible. NO synthase (iNOS). Surfactant inhibits LPS-induced. NO formation in a concentration-dependent manner;. NO production is inhibited by approximately 50 and approximately 75% at surfactant levels of 100 and 200 microg phospholipid/ml, respectively. The inhibition is not due to surfactant interference with the interaction of LPS with the cells or to disruption of the formation of iNOS mRNA. Also, surfactant does not seem to reduce. NO formation by directly affecting iNOS activity or by acting as an antioxidant or radical scavenger. However, in the presence of surfactant, there is an approximately 80% reduction in the amount of LPS-induced iNOS protein in the cells. LPS-induced. NO production is inhibited by Survanta, a surfactant preparation used in replacement therapy, as well as by natural surfactant. NO formation is not affected by the major lipid components of surfactant or by two surfactant-associated proteins, surfactant protein (SP) A or SP-C. However, the hydrophobic SP-B inhibits. NO formation in a concentration-dependent manner;. NO production is inhibited by approximately 50 and approximately 90% at SP-B levels of 1-2 and 10 microgram/ml, respectively. These results show that lung surfactant inhibits LPS-induced. NO production by alveolar macrophages, that the effect is due to a reduction in iNOS protein levels, and that the surfactant component responsible for the reduction is SP-B.

Animals↗
PubMed1999

Optic disc size in ocular hypertension.

PURPOSE: To study the optic disc size in eyes with ocular hypertension (OHT) in comparison to primary open-angle glaucoma (POAG) and normals. METHODS: Optic disc photographs obtained with the Nidek 3dx NM camera were digitized (Nikon coolscan) and disc area calculated using Littmann correction in a randomly chosen eye of 28 OHT, 42 POAG and 30 normal subjects. OHT was defined as increased intraocular pressure with no disc or field changes suggestive of glaucoma with open angles. RESULTS: The optic disc area in OHT was 9.47 +/- 1.09 mm2; 12.27 +/- 2.87 mm2 in POAG; and 12.11 +/- 2.83 mm2 in normal individuals. CONCLUSION: Using magnification corrected morphometry and the criteria for OHT diagnosis, the optic disc area in OHT was significantly smaller (p < 0.0001) in POAG and normals.

Glaucoma, Open-Angle↗
PubMed1997

The association of plasma IL-6 levels with functional disability in community-dwelling elderly.

BACKGROUND: IL-6 is a multifunctional cytokine that has been shown to increase with age. METHODS: Plasma IL-6 was measured by ELISA in 1,727 community-dwelling elderly subjects whose blood was drawn during the third in-person survey of the Duke Established Populations for Epidemiologic Studies of the Elderly (EPESE). Demographics, functional status (disability), and disease states were determined. Correlations of these factors with IL-6 were analyzed with Spearman's Rho while differences between groups were assessed by Wilcoxon test. RESULTS: IL-6 levels were higher with age (p = .0001) even in this older population (> 70 years). There was a positive correlation between IL-6 and functional disability for each of the functional status measures (p = .0001), as well as a correlation between self-rated health and IL-6. Significantly higher median levels of IL-6 were found in subjects reporting prevalent cancer, heart attack, and high blood pressure, but not diabetes or arthritis. The association between age and functional status with high IL-6 remained when all other variables were controlled, in multivariable analysis. CONCLUSIONS: This association between increased plasma IL-6 levels and functional status suggests that dysregulation of IL-6 may be related to the functional disability seen with aging, and that IL-6 may be useful as a component of an overall marker of health.

Aged↗
PubMed1997

Alterations in stimulus-induced integrin expression in peripheral blood neutrophils of patients with diabetic retinopathy.

Adhesion molecule expression on peripheral blood leukocytes from diabetic patients with severe retinopathy and age-matched control subjects was assessed. Expression of CD11b, CD18, and L-selectin was measured on granulocytes and lymphocytes in whole blood within 1 hour of blood collection. Adhesion molecule expression was determined at 4 degrees C, 37 degrees C, and after stimulation with one of the chemotactic peptides, N-formyl-methionyl-leucyl-phenyl-alanine or beta-phorbol 12-myristate 13-acetate. There were no differences between diabetics and controls in CD11b expression in neutrophils at 4 degrees C, 37 degrees C, or after N-formyl-methionyl-leucyl-phenylalanine stimulation. However, during stimulation with beta-phorbol 12-myristate 13-acetate, the increase in CD11b expression in neutrophils from patients with diabetes was significantly less than in controls. In neutrophils, there was no difference between the control and diabetic participants in CD18 expression at 4 degrees C, but after warming the cells to 37 degrees C, the expression was significantly higher in patients with diabetes. The difference became even more apparent after N-formyl-methionyl-leucyl-phenyl-alanine stimulation. The increase in CD18 expression after beta-phorbol 12-myristate 13-acetate stimulation of neutrophils was similar in control and diabetic participants. There was no difference in L-selectin expression in neutrophils under any conditions. There was no difference in adhesion molecule expression on lymphocytes under similar conditions. In summary, these observations indicate that integrin expression of neutrophils from patients with diabetes and retinopathy is altered after stimulation with neutrophil-activating agents. The changes were integrin-, stimulus-, and cell-specific, which suggests that the signal transduction mechanisms may be altered in diabetic neutrophils. These alterations may be responsible for abnormal leukocyte/endothelial interactions and microvascular complications in diabetic retinopathy.

Adult↗
PubMed1996

Development of malathion resistance in Culex quinquefasciatus Say (Diptera: Culicidae).

A malathion resistant colony of C. quinquefasciatus was developed in the laboratory. LC50 and LC90 for larvae were calculated at every generation and the values were 0.3 ppm and 1.13 ppm for first generation and 61.09 ppm, 136.3 ppm for 25th generation respectively. The fold increase in LC50 and LC90 were 2036 and 2726 folds respectively. Cross resistance against propoxur and chlorpyrifos showed 6.64 and 6.52 fold and 600 and 720 fold increase in their LC50 and LC90 values respectively. Triphenyl phosphate (TPP) and piperonyl butoxide (PB) were used as synergists and TPP indicated proportional decrease in LC50 and LC90 values while not much change was observed with PB. No change in biotic potential (larval hatchability, adult emergence and male and female ratio) between susceptible and malathion resistant colonies was observed.

Animals↗
PubMed1995

Smaller auditory P300 amplitude in schizophrenics in remission.

The P300 event-related potential (ERP) was recorded using the auditory oddball paradigm in 12 (6 male) schizophrenic (DSM-IIIR) patients in rigorously defined clinical remission. The ERP was also recorded in 10 (5 male) age-, sex- and education-matched control subjects. ERP latencies and amplitude were measured at Cz and Pz recording sites. Mean latencies of the P300 in schizophrenic patients in remission at Cz [343.6 +/- 31 (SD) ms] and Pz (346.15 +/- 30 ms) did not differ from those of normals (Cz: 332.8 +/- 23 ms, Pz: 323 +/- 38 ms). The P300 ERP amplitude was significantly (p < 0.05) smaller in schizophrenics in remission at both Cz (9.2 +/- 4.4 microV) and Pz (8.8 +/- 4.4 microV) than in normals (Cz: 13.3 +/- 2.90 microV; Pz: 12.71 +/- 4.18 microV). The significance of the smaller auditory P300 amplitude in schizophrenia is discussed.

Adult↗
PubMed1995

Tumor necrosis factor, natural killer activity and other measures of immune function and inflammation in elderly men with heart failure.

OBJECTIVE: To determine the status of tumor necrosis factor (TNF) and other measures of immunity and inflammation in chronic heart failure (CHF) in the elderly. DESIGN: Comparative survey study of subjects with heart failure and age-matched controls. SETTINGS: University affiliated tertiary care VA Medical Center, Heart Failure Clinic. PATIENTS: Twenty men with New York Class II and III heart failure and 17 age-matched controls. INTERVENTIONS: None. MAIN OUTCOME MEASURE: Levels of lymphocyte mitogenesis, TNF, natural killer (NK) cell activity, elastase-alpha 1-antitrypsin (E/alpha) and cross-linked fibrin D-dimers (XDP). RESULTS: TNF levels (p = 0.27), NK activity (p = 0.56), and lymphocyte mitogenesis (p = 0.67) were similar in patients and controls. E/alpha levels were somewhat lower in CHF patients (p = 0.05) and XDP were similar (p = 0.59). However, TNF levels were significantly related to NK activity and to E/alpha activity in elderly men with heart failure but not controls. XDP were positively related to NK in heart failure patients but not controls. CONCLUSION: TNF and other measures of immune function and inflammation do not appear to be significantly elevated in elderly patients with heart failure of moderate severity. However, significant relationships exist between TNF, NK activity, XDP and E/alpha in the heart failure patients only, suggesting that immune activation and subclinical inflammation does exist in these patients.

Aged↗
PubMed1995

Synthesis and secretion of proteins by the human proliferative, secretory, decidual and hyperplastic endometrium.

Human endometria were analysed for the synthesis and secretion of proteins following short term culture of human endometrial tissue in the presence of 35S-methionine. During the menstrual cycle secretory proteins of molecular weight (MW) 30, 35, 45, 50, 59, 74, 97 and 135 kDa showed increased synthesis during the proliferative phase. The synthesis of these proteins decreased in the secretory phase but the induction of a 26 kDa protein in the early secretory phase and a 28 kDa protein in the late secretory phase was observed. The synthesis of the above secretory proteins of the human endometrium was also confirmed by two dimensional gel electrophoresis. Further, the results demonstrated that the secretory protein profile of human decidual endometria and endometria exhibiting irregular ripening was identical to that of normal secretory phase endometria. But, endometria exhibiting hyperplasia, cystic glandular hyperplasia and adenomatous glandular hyperplasia presented similar secretory protein profiles which were identical with the secretory protein profile of normal proliferative phase endometrium. The present study confirms that a number of proteins are synthesised by the human endometrium during the normal menstrual cycle and during pregnancy. It also provides data for the first time on the proteins secreted by the endometria exhibiting irregular ripening, hyperplasia, cystic glandular hyperplasia and adenomatous glandular hyperplasia.

Adult↗
PubMed1995

Comparative activity of three repellents against bedbugs Cimex hemipterus (Fabr.).

Comparative activity of three repellents viz., diethyl-m-toluamide (DEET), diethyl phenyl-acetamide (DEPA) and dimethylphthalate (DMP) against bedbugs Cimex hemipterus (Fabr) was studied by applying repellent solution on the shaven skin of rabbits. DEET (Tech. grade) 20mgai/cm2 exhibited 93 and 83 per cent repellency after 2 and 8 h respectively, while DEPA (Tech. grade) at this concentration exhibited 90 and 71 per cent repellency. DEET and DEPA at 75 per cent concentration (15mgai/cm2) showed 85 and 78 per cent repellency up to 2 h and 52 and 42 per cent repellency 6 h after treatment respectively. The repellent activity was also found to be concentration and time of treatment dependent in respect of DEET and DEPA. DMP (Tech. grade) did not show any appreciable repellent activity at any concentration tested. Further, the blood intake by C. hemipterus following treatment with various concentrations of repellents was found to decrease with increase in the concentration of repellents.

Animals↗